Modal Verbs Showing Obligation Full obligation; must, partial obligation; should, partial obligation; ought to (less common);
English Modals, Examples and Uses (Very Important) Uses of can, be able to, can’t, could, may, might, must, have to, need to, needn’t, musn’t, don’t have to, should, ought …
Modal Verbs: Advice (Should, Ought to, Had better);